Tags: Protein.
Streptavidin /ˌstrɛpˈtævədən/ is a 52.8 kDa protein purified from the bacterium Streptomyces avidinii. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin (also known as vitamin B7 or vitamin H). With a dissociation constant (Kd) on the order of ≈10−14 mol/L the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature.
